netty发消息时提示 unsupported message type: [B (expected: ByteBuf, FileRegion)

解决办法，新加一个Encoder

public class ByteArrayToBinaryEncoder extends MessageToMessageEncoder<byte[]> {
    @Override
    protected void encode(ChannelHandlerContext ctx, byte[] msg, List<Object> out) throws Exception {
        out.add( new BinaryWebSocketFrame(Unpooled.wrappedBuffer(msg)));
    }
}